Burying submarine cables is expensive, requiring as it does a dedicated ship having the necessary equipment, particularly for burying the cable in the seabed. Such equipment conventionally comprises a plough device which requires substantial amounts of power from the ship in order to operate and tow it. For example the plough has an attitude control, controls to lift and lower the plough, television cameras to check if the cable is entering the plough correctly, magnetometer to check if the cable has been properly buried behind the plough, and a depresser arm which lifts and closes when a repeater of the cable link passes through the plough. Such a plough has three lines extending from the ship down to the plough, namely an umbilical cable for the various controls, a tow wire to tow the plough, and it has the cable itself which is to be buried.
One form of plough device for burying cables is discussed in specifcation No. GB-A-1,117,333.
A particular problem that has been experienced with apparatus of this type is that of guiding the cable into the burying device. Conventional guides are bulky and, where a long guide is necessary, presents a significant storage problem on the cable-laying vessel.
It is an object of the invention to minimise or to overcome this disadvantage.